Outdoor sauna permits compared: what we could verify, and what to ask

Short version: no single European rule decides whether a sauna cabin or a plunge pool needs a permit. It depends on the country, the region, the municipality and the plot. We do not guess. We give you the verified points, with the source named, and the questions that get you a clear answer from the people who decide.

How to read this note

Each country section lists, first, what we verified on an official or primary source, with the source and the year, and second, what we could not verify and phrase as a question. Nothing here is legal advice. If a rule matters to a purchase, ask the authority in writing and keep the reply.

Spain: regional rules, municipal answers

Spain has no single rule for a sauna cabin or a plunge pool in a garden. Municipalities and regions decide, and the answer can differ from one street to the next. What we verified on the official text is narrower, and useful.

Portugal: the RJUE, and a council that can add to it

The urban-building regime (RJUE, Decree-Law 555/99, as consolidated on the Diário da República and viewed on 11 October 2026) exempts works of low urban relevance, “obras de escassa relevância urbanística”, from a licence and from prior communication (Article 6). Article 6-A lists them, among them an annex of up to 10 m² and 2.2 m high that does not face the public road, garden greenhouses, and “equipamento lúdico ou de lazer” associated with the main building and smaller than it, and lets each council add its own list. Classified buildings are excluded.

Pools are not on that list. The same text places the building of a pool associated with a main building among the operations subject to prior communication (Article 4(4)(j)). Whether a sauna cabin counts as a leisure installation or as an annex, and what your council adds, is for the câmara municipal to say: ask in writing and keep the answer.

Ireland: exempted development, with conditions

Irish planning law exempts some small structures in the curtilage of a house from planning permission. The rule that matters is Class 3 of Part 1 of Schedule 2 of the Planning and Development Regulations 2001, as substituted by S.I. No. 338 of 2026, in operation from 27 July 2026. It covers a tent, awning, shade or other object, greenhouse, garage, store, shed or other similar structure within the curtilage of a house, on these conditions:

• not forward of the front wall of the house;
• a total area of such structures, with any existing ones, of no more than 30 m² (it was 25 m² before July 2026);
• the private open space to the rear or side of the house must not fall below 25 m²;
• a structure to the side must match the finishes of the house;
• a height of no more than 4 m with a tiled or slated pitched roof, and 3 m in any other case;
• not used for human habitation, or for any purpose other than one incidental to the enjoyment of the house.

A sauna is not named in that class. Whether a glass cabin is a “shed or other similar structure” incidental to the enjoyment of the house is a question for your local authority, and protected structures, conservation areas and a house that has already used its exemptions change the answer. A pool is not named in that class: ask your local authority what applies to a plunge pool.

Cyprus: what we could not verify

We could not reach an official Cyprus source for building or planning rules on small garden structures, so we state none. Ask the planning authority and the local authority which of these applies to your plot: a building permit, a planning permit, an exemption for minor works, or nothing at all. Use the five questions below.

Holiday lets, in every country

Regulation (EU) 2024/1028 on short-term accommodation rental data applies from 20 May 2026. It does not itself create a registration duty, but where a registration procedure exists the host must give the platform the number, and the platform must make sure the listing shows it clearly and check it at random (EUR-Lex, OJ of 29 April 2024, Articles 4, 6 and 7). Hotels and campsites are outside it.

Registers are national or regional, so ask the authority where the property stands which one applies, and keep the number on the listing.

The five questions for any town hall

1. What is the plot registered as? Urban, rural, protected, coastal, agricultural: the category decides most of what follows.
2. Is a free-standing cabin treated as a building, a structure, an outbuilding or minor works, and does it need a notification or a licence?
3. Is a plunge pool a swimming pool for the purposes of the rules, and does it need a separate safety or health registration?
4. What are the limits of size, height and distance from boundaries for anything built in the garden?
5. Which documents does the authority want: drawings, a structural note, an electrician's certificate, the neighbours' consent?

What to have ready

• A plan of the plot with the cabin and the pool drawn in: our 3D layout is made for this.
• Dimensions, heights and the weight of each item: our one-page data sheet.
• The electrical load and the proposed circuit: the layout lists them.
• A photograph of the site and its surroundings.
• If the property is let, the registration details and the insurer's name.

For electrical questions, see villa mains or three-phase; for the pool's water care, hygiene for commercial plunge pools. Each place has its own page under where we work.

The two products these rules touch most are garden saunas and plunge pools; the country pages (Spain, Portugal, Ireland and Cyprus) carry the local questions.